Water purification apparatus for use in laboratories and healthcare facilities are well known. Generally they involve the reduction and/or removal of contaminants and impurities to very low levels from a water source, as well as any impurities originating from within the apparatus itself. They typically contain a variety of technologies that remove particles, bacteria, ionic species and organic substances and/or molecules.
One very important parameter for many purified water applications is that the bacteria levels are less than prescribed limits. As well as limits on viable bacteria, frequently there are limits on bacterial by-products such as endotoxins, RNase, DNase, alkaline phosphatase, etc., as each of these impurities can have detrimental effects on specific analysis or research.
Micro-organisms, including bacteria and their by-products, are routinely removed from high purity water by a number of techniques, including, but not limited to, reverse osmosis, micro-filtration, ultrafiltration, adsorption and UV irradiation. Despite this array of technologies, and maintaining active recirculation of the purified water, micro-organisms can, under some situations, still develop within the water purification apparatus, and in extreme cases can form biofilms on the surface of components, tubing, pumps etc., leading to contamination of the highly purified water and in some cases leading to a requirement to replace the components themselves.
Regular sanitisation of water purification apparatus is therefore required to ensure optimum performance of the apparatus, and to reduce and hopefully eliminate any contaminants in the water purification apparatus, such as bacteria or micro-organisms adhearing to a surface therein.
Sanitisation of water purification apparatus is conventionally carried out by taking the apparatus ‘off line’, followed by the addition of hazardous chemicals which are generally circulated for a set period within the apparatus to ensure all micro-organisms are destroyed, before being rinsed or flushed out of the apparatus. Naturally, it is important that all the chemicals are removed prior to return of the apparatus to normal usage, as cleaning chemicals are generally damaging or otherwise dangerous to the activities that the purified water is being applied to.
Whilst cleaning chemicals can be added manually, it is preferred for them to be added from a dedicated container able to ensure the correct introduction, supply and dosage of the chemical or substance. Our WO 03/076321 A1 shows a separable component adapted to sanitise and/or clean one or more parts of a host water treatment apparatus. The component is adapted to properly co-operate with the host apparatus, to ensure the correct introduction and supply of the sanitant in the component into the host apparatus.
However, all known sanitising systems and apparatus still require the rinsing and flushing out of the chemicals and residues from the water purification apparatus through an outlet and passed to a drain or to a waste receptacle. These are flushed out by a stream or a series of streams of fresh water, all of which also goes to the drain or to the waste receptacle. Naturally, it is desired to ensure the removal of the cleaning chemicals and residues to the greatest extent, such that significant volumes of water are required, especially to flush away the last remaining fractions of the cleaning chemicals and residues.
Waste receptacles are required where the chemicals and residues are not allowed to be passed to a drain due to local or site limitations, also requiring separate off-site disposal. This off-site disposal increases the complication and cost of the sanitisation process.
Moreover, the rinsing and flushing out of the chemicals from the water purification apparatus also takes some time to carry out, adding to the expensive downtime for the apparatus until it is able to be operational again.
Purified water provided by a water purification apparatus can be dispensed directly from the apparatus, or be supplied to a water distribution apparatus such as a ring main for dispense in one or more, usually separate, locations. Such water distribution apparatus also require regular sanitisation as described above for water purification apparatus, as they suffer the same or similar problems as described above.